Mhale00 & Raylar Kit
10-10-2005 | 11:28 AM
#81
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From: LONG ISLAND-NY
Re: Mhale00 & Raylar Kit
Originally Posted by Steve Zuckerman
Linster,
They will run, but typically not the way the factory sends them out. They are using a very high X-dimension for such a large single engine boat. The boat lacks the hydrodynamic lift needed to free it up with moderate horsepower, and it is still weight sensitive (placement and load) with horsepower. That's why some people are having success with drive spacers. It does work better as the horsepower and speed goes up. I've worked pretty hard to get mine to 85. I used the Imco case to load the prop, and the P5-X to get enough blade area to lift the boat. The factory should make everyone aware of the P5-X prop. It does help the high X dimension issues (slow holeshot/high propeller slip #s) tremendously. The older padvee Heats ('99 and back) used a much deeper X-dimension that gave better all round performance.
On the other hand, it is a great looking, smooth riding boat with a spacious cabin, for it's size.
I think the step is just too conservative to be of much help freeing the boat up. If you look at the steps on the Flame, they are much taller.
Another small step on the Heat, or increasing the height of the existing step would help tremendously. My best friend's 29' Fountain has a single step in the same position (fore and aft) on the hull, but it's much deeper, like the Flame's. Just my 2 cents...............
Regards,
Steve
They will run, but typically not the way the factory sends them out. They are using a very high X-dimension for such a large single engine boat. The boat lacks the hydrodynamic lift needed to free it up with moderate horsepower, and it is still weight sensitive (placement and load) with horsepower. That's why some people are having success with drive spacers. It does work better as the horsepower and speed goes up. I've worked pretty hard to get mine to 85. I used the Imco case to load the prop, and the P5-X to get enough blade area to lift the boat. The factory should make everyone aware of the P5-X prop. It does help the high X dimension issues (slow holeshot/high propeller slip #s) tremendously. The older padvee Heats ('99 and back) used a much deeper X-dimension that gave better all round performance.
On the other hand, it is a great looking, smooth riding boat with a spacious cabin, for it's size.
I think the step is just too conservative to be of much help freeing the boat up. If you look at the steps on the Flame, they are much taller.
Another small step on the Heat, or increasing the height of the existing step would help tremendously. My best friend's 29' Fountain has a single step in the same position (fore and aft) on the hull, but it's much deeper, like the Flame's. Just my 2 cents...............
Regards,
Steve
10-11-2005 | 09:40 AM
#82
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Joined: Sep 2005
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From: Missouri
Re: Mhale00 & Raylar Kit
Originally Posted by LIOPA
YUP.....Lonnie had changed the X on the 525/ITS boat per our request to achieve better results. It seems that helped the performance and out of hole numbers as well.
I have been following your discussions on the 'X' dimension and drive spacer issue with great interest as to its effect on top end.
I am having trouble understanding why reducing the 'X' dimension by itself should improve top end other than the lower unit will simultaneously move deeper below the water running surface as the 'X' dimension is reduced for a given hull. Adding a drive spacer provides the same identical result of moving the lower unit deeper below the water running surface. Is this only to reduce % slip at WOT with high trim angle that usually results in increased prop surfacing by forcing the prop to run deeper? And/or to improve prop bite for better bow lift? Am I on track or is there something else in play here?
Why would reducing the 'X' dimension improve hole shot?
10-11-2005 | 10:33 AM
#83
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From: Nashvegas, TN
Re: Mhale00 & Raylar Kit
Originally Posted by Rage
I have been following your discussions on the 'X' dimension and drive spacer issue with great interest as to its effect on top end.
I am having trouble understanding why reducing the 'X' dimension by itself should improve top end other than the lower unit will simultaneously move deeper below the water running surface as the 'X' dimension is reduced for a given hull. Adding a drive spacer provides the same identical result of moving the lower unit deeper below the water running surface. Is this only to reduce % slip at WOT with high trim angle that usually results in increased prop surfacing by forcing the prop to run deeper? And/or to improve prop bite for better bow lift? Am I on track or is there something else in play here?
Why would reducing the 'X' dimension improve hole shot?
I am having trouble understanding why reducing the 'X' dimension by itself should improve top end other than the lower unit will simultaneously move deeper below the water running surface as the 'X' dimension is reduced for a given hull. Adding a drive spacer provides the same identical result of moving the lower unit deeper below the water running surface. Is this only to reduce % slip at WOT with high trim angle that usually results in increased prop surfacing by forcing the prop to run deeper? And/or to improve prop bite for better bow lift? Am I on track or is there something else in play here?
Why would reducing the 'X' dimension improve hole shot?
The concept of a high X dimension comes from race boats, both inboard and outboard. The biggest single source of high speed drag on all boats is their gearcase. Stick your finger in the water at 50 mph and you'll see what I mean. Water is an incompressible fluid. Raising the gearcase does several very positive things.
The biggest is decreased drag. The second is semi-surfacing the propeller. Air is compressible, and turning a propeller in this air/water environment generally allows you to run more pitch with the same amount of horsepower. The other thing that you won't hear much about, but is generally true (there are many variables of hull/drive/propellers) is that high X dimensions reduce high speed chinewalk.
Another general rule is that the higher the horsepower to weight ratio of a given boat, the higher you can go on the X dimension.
This race/high perf concept holds true on most performance hulls too. The biggest variables with "pleasure boats" though is the hp/weight ratio (I think you can buy a Rage with a small block to a 525) and load variation ( 1 to 5 people). You've probably noticed your boat is faster with a light load, because that increases your HP to weight ratio, for instance. I'm sure you have read many of us comment that our boats vary quite a bit in perfomance, depending on total weight load, weather, and water conditions.
Race boats generally have a much smaller variation in weight loads. Even then, they are generally faster later in the race as they burn off their fuel loads. Gas weighs 6 lbs. per gallon, so 250 gallons X 6 = 1500lbs.
Conversely, if you go too high on the XD for a given hull/engine/drive/ propeller combination, you will lose holeshot and top end. This is because a shallow running propeller doesn't have the mechanical leverage to lift the hull as well. This can be addressed 4 ways that I am aware of:
Increased propeller blade area (going from 4 to 5), rake, and cupping; increased setback (Merc ITS or Stellings box); drive spacers to lower the prop; gearcase design (going from a stock Bravo to an Imco or Sportmaster, etc., or adding a nosecone) to load the prop better.
So, adapting race boat technology to high performance boats does work, it just takes more tweaking to get the perfect setup.
Regards,
Steve
Last edited by Steve Zuckerman; 10-11-2005 at 10:55 AM.
10-11-2005 | 10:46 AM
#84
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Joined: Sep 2005
Posts: 1,987
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From: Missouri
Re: Mhale00 & Raylar Kit
Originally Posted by LIOPA
YUP.....Lonnie had changed the X on the 525/ITS boat per our request to achieve better results. It seems that helped the performance and out of hole numbers as well.
Did Lonnie increase or decrease your 'X' dimension?
Did the change increase your top end @WOT as well as faster hole shot?
10-11-2005 | 10:56 AM
#85
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Joined: Sep 2005
Posts: 1,987
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From: Missouri
Re: Mhale00 & Raylar Kit
Originally Posted by Steve Zuckerman
Rage,
The concept of a high X dimension comes from race boats, both inboard and outboard. The biggest single source of high speed drag on all boats is their gearcase. Stick your finger in the water at 50 mph and you'll see what I mean. Water is an incompressible fluid. Raising the gearcase does several very positive things.
The biggest is decreased drag. The second is semi-surfacing the propeller. Air is compressible, and turning a propeller in this air/water environment generally allows you to run more pitch with the same amount of horsepower. The other thing that you won't hear much about, but is generally true (there are many variables of hull/drive/propellers) is that high X dimensions reduce high speed chinewalk.
Another general rule is that the higher the horsepower to weight ratio of a given boat, the higher you can go on the X dimension.
This race/high perf concept holds true on most performance hulls too. The biggest variables with "pleasure boats" though is the hp/weight ratio (I think you can buy a Rage with a small block to a 525) and load variation ( 1 to 5 people). You've probably noticed your boat is faster with a light load, because that increases your HP to weight ratio, for instance. I'm sure you have read many of us comment that our boats vary quite a bit in perfomance, depending on total weight load, weather, and water conditions.
Race boats generally have a much smaller variation in weight loads. Even then, they are generally faster later in the race as they burn off their fuel loads. Gas weighs 6 lbs. per gallon, so 250 gallons X 6 = 1500lbs.
Conversely, if you go too high on the XD for a given hull/engine/drive/ propeller combination, you will lose holeshot and top end. This is because a shallow running propeller doesn't have the mechanical leverage to lift the hull as well. This can be addressed 4 ways that I am aware of:
Increased propeller blade area (going from 4 to 5), rake, and cupping; increased setback (Merc ITS or Stellings box); drive spacers to lower the prop; gearcase design (going from a stock Bravo to an Imco or Sportmaster, etc., or adding a nosecone) to load the prop better.
So, adapting race boat technology to high performance boats does work, it just takes more tweaking to get the perfect setup.
Regards,
Steve
The concept of a high X dimension comes from race boats, both inboard and outboard. The biggest single source of high speed drag on all boats is their gearcase. Stick your finger in the water at 50 mph and you'll see what I mean. Water is an incompressible fluid. Raising the gearcase does several very positive things.
The biggest is decreased drag. The second is semi-surfacing the propeller. Air is compressible, and turning a propeller in this air/water environment generally allows you to run more pitch with the same amount of horsepower. The other thing that you won't hear much about, but is generally true (there are many variables of hull/drive/propellers) is that high X dimensions reduce high speed chinewalk.
Another general rule is that the higher the horsepower to weight ratio of a given boat, the higher you can go on the X dimension.
This race/high perf concept holds true on most performance hulls too. The biggest variables with "pleasure boats" though is the hp/weight ratio (I think you can buy a Rage with a small block to a 525) and load variation ( 1 to 5 people). You've probably noticed your boat is faster with a light load, because that increases your HP to weight ratio, for instance. I'm sure you have read many of us comment that our boats vary quite a bit in perfomance, depending on total weight load, weather, and water conditions.
Race boats generally have a much smaller variation in weight loads. Even then, they are generally faster later in the race as they burn off their fuel loads. Gas weighs 6 lbs. per gallon, so 250 gallons X 6 = 1500lbs.
Conversely, if you go too high on the XD for a given hull/engine/drive/ propeller combination, you will lose holeshot and top end. This is because a shallow running propeller doesn't have the mechanical leverage to lift the hull as well. This can be addressed 4 ways that I am aware of:
Increased propeller blade area (going from 4 to 5), rake, and cupping; increased setback (Merc ITS or Stellings box); drive spacers to lower the prop; gearcase design (going from a stock Bravo to an Imco or Sportmaster, etc., or adding a nosecone) to load the prop better.
So, adapting race boat technology to high performance boats does work, it just takes more tweaking to get the perfect setup.
Regards,
Steve
What you describe is what I am familiar with. What I am confused about is that in some of the earlier posts in this thread it comments indicate that DECREASED 'X' factor increase top end speed at WOT and well as hole shot. The latter I can comprehend. The former is puzzling and what I am trying to bore down on and understand. A decreased 'X' factor would push the gear case deeper in the water for more drag as you say. A deeper gear case could improve prop bite for better bow lift if the current position is too shallow?
What do you think?
Regards!
10-11-2005 | 11:12 AM
#86
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Joined: Nov 2002
Posts: 2,621
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From: Nashvegas, TN
Re: Mhale00 & Raylar Kit
Rage:
It's simply a matter of "locking up the propeller". You can do that by "burying" it (lowering the XD). That will work. The prop then can lift the hull at high speed because it has more mechanical leverage, being deeper in the water. Keep in mind this ALWAYS changes, depending on weight placement and total weight (fuel/passengers/gear). Lower will generally give you better all round performance, but you may give up a few mph with a light load.
The easy way to tell if you boat has enough lift is to have someone watch or video your boat at high speed who is capable of evaluating it's "set".
Rather than burying the gearcase, I would try propwork.
I would speak with Julie at Throttle Up. I have a feeling you will be VERY impressed with what she and Matt can do with your Bravo props. You may have also read where BobL, Dave and I have commented positively on the Hydromotive P5-X.
That design works perfectly on high XD step hulls. It works great on the Heat, and I bet it will do the same on the Rage.
I would definitely demo one.
Regards,
Steve
It's simply a matter of "locking up the propeller". You can do that by "burying" it (lowering the XD). That will work. The prop then can lift the hull at high speed because it has more mechanical leverage, being deeper in the water. Keep in mind this ALWAYS changes, depending on weight placement and total weight (fuel/passengers/gear). Lower will generally give you better all round performance, but you may give up a few mph with a light load.
The easy way to tell if you boat has enough lift is to have someone watch or video your boat at high speed who is capable of evaluating it's "set".
Rather than burying the gearcase, I would try propwork.
I would speak with Julie at Throttle Up. I have a feeling you will be VERY impressed with what she and Matt can do with your Bravo props. You may have also read where BobL, Dave and I have commented positively on the Hydromotive P5-X.
That design works perfectly on high XD step hulls. It works great on the Heat, and I bet it will do the same on the Rage.
I would definitely demo one.
Regards,
Steve
Last edited by Steve Zuckerman; 10-11-2005 at 11:23 AM.
10-11-2005 | 11:43 AM
#87
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Joined: Sep 2005
Posts: 1,987
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From: Missouri
Re: Mhale00 & Raylar Kit
Originally Posted by Steve Zuckerman
Rage:
It's simply a matter of "locking up the propeller". You can do that by "burying" it (lowering the XD). That will work. The prop then can lift the hull at high speed because it has more mechanical leverage, being deeper in the water. Keep in mind this ALWAYS changes, depending on weight placement and total weight (fuel/passengers/gear). Lower will generally give you better all round performance, but you may give up a few mph with a light load.
The easy way to tell if you boat has enough lift is to have someone watch or video your boat at high speed who is capable of evaluating it's "set".
Rather than burying the gearcase, I would try propwork.
I would speak with Julie at Throttle Up. I have a feeling you will be VERY impressed with what she and Matt can do with your Bravo props. You may have also read where BobL, Dave and I have commented positively on the Hydromotive P5-X.
That design works perfectly on high XD step hulls. It works great on the Heat, and I bet it will do the same on the Rage.
I would definitely demo one.
Regards,
Steve
It's simply a matter of "locking up the propeller". You can do that by "burying" it (lowering the XD). That will work. The prop then can lift the hull at high speed because it has more mechanical leverage, being deeper in the water. Keep in mind this ALWAYS changes, depending on weight placement and total weight (fuel/passengers/gear). Lower will generally give you better all round performance, but you may give up a few mph with a light load.
The easy way to tell if you boat has enough lift is to have someone watch or video your boat at high speed who is capable of evaluating it's "set".
Rather than burying the gearcase, I would try propwork.
I would speak with Julie at Throttle Up. I have a feeling you will be VERY impressed with what she and Matt can do with your Bravo props. You may have also read where BobL, Dave and I have commented positively on the Hydromotive P5-X.
That design works perfectly on high XD step hulls. It works great on the Heat, and I bet it will do the same on the Rage.
I would definitely demo one.
Regards,
Steve
I am fine with the general all around performance of my set up. What I am after is improved top end/reduced %slip at WOT. If a reduced 'X' factor gets me more top end because of more bow lift and /or less slip then thats what I want to do. If conversely it gives me more bow lift but slower top end for whatever reason then no. Same with the Hydromotive P5-X you mention. A demo seems in order.
I actually made contact with Julie on another thread also pursuing info on the drive spacer approach.
I would still like to hear from a late model Rage owner that has tried a drive spacer on a 496HO.
Regards!
10-11-2005 | 01:32 PM
#88
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Joined: Nov 2002
Posts: 2,621
Likes: 1
From: Nashvegas, TN
Re: Mhale00 & Raylar Kit
Rage:
Keep in mind that all this begins and ends with the propeller. There is more performance to be lost or found here than on any other component on our boats.
Propellers are our version of tires on race cars. The best chassis/engine combo won't work unless it can transmit it's forces to the pavement.
It has always been my theory to build the "propeller to the boat", not build the boat to the propeller(s).
Propeller technology continues to evolve, just as hull, engine, and drive technologies do. In some cases, propeller technology is catching up to drive and hull technology. Again, I would let Matt and Julie work their magic on your prop(s) before resorting to a lower XD. The other alternative, though expensive, is also preferable in trying/building a 5 blade. What the 5 blade does is add enough blade area, with that extra blade, to carry your hull, even with an elevated XD.
An elevated XD, isn't a bad thing. It's a response by the factory to advancing drive and propeller technology. Also keep in mind that some of this is compromise.........sometimes mods that deliver extra top end, give up some bottom end, and vice versa.
My best friend has a 29' Fountain with the same motor (575SCi) I have. Since I've done my recent round of mods, I can blister him out of the hole, and at pretty much any on plane punch, but he still has 2 or 3 MPH on me top end. His boat slips and cavitates coming on plane (like mine used to).
His boat won't plane off without using tabs. Mine will. They are both great boats, but I've fixed my bottom end and acelleration issues and he hasn't. He doesn't care because he has great top end, and these aren't drag boats. My point is it's hard to have everything, even though we all want it.
Good luck with your Rage and keeps us posted on your progress.
Steve
Keep in mind that all this begins and ends with the propeller. There is more performance to be lost or found here than on any other component on our boats.
Propellers are our version of tires on race cars. The best chassis/engine combo won't work unless it can transmit it's forces to the pavement.
It has always been my theory to build the "propeller to the boat", not build the boat to the propeller(s).
Propeller technology continues to evolve, just as hull, engine, and drive technologies do. In some cases, propeller technology is catching up to drive and hull technology. Again, I would let Matt and Julie work their magic on your prop(s) before resorting to a lower XD. The other alternative, though expensive, is also preferable in trying/building a 5 blade. What the 5 blade does is add enough blade area, with that extra blade, to carry your hull, even with an elevated XD.
An elevated XD, isn't a bad thing. It's a response by the factory to advancing drive and propeller technology. Also keep in mind that some of this is compromise.........sometimes mods that deliver extra top end, give up some bottom end, and vice versa.
My best friend has a 29' Fountain with the same motor (575SCi) I have. Since I've done my recent round of mods, I can blister him out of the hole, and at pretty much any on plane punch, but he still has 2 or 3 MPH on me top end. His boat slips and cavitates coming on plane (like mine used to).
His boat won't plane off without using tabs. Mine will. They are both great boats, but I've fixed my bottom end and acelleration issues and he hasn't. He doesn't care because he has great top end, and these aren't drag boats. My point is it's hard to have everything, even though we all want it.
Good luck with your Rage and keeps us posted on your progress.
Steve
Last edited by Steve Zuckerman; 10-11-2005 at 03:26 PM.
10-11-2005 | 02:47 PM
#89
Member #154
Joined: Oct 2000
Posts: 8,000
Likes: 1,072
From: SW CT & Long Island Sound
Re: Mhale00 & Raylar Kit
Originally Posted by LIOPA
Hey Steve....let me know what issue. Does sound interesting.
In the list you posted add wave/chop conditions also play a big part with stepped bottoms as well.
In the list you posted add wave/chop conditions also play a big part with stepped bottoms as well.
Sorry Paul...I went through all my back issues and didn't find the one article I really wanted to save LOL!! I sent a note to PRA asking for the issue that it was in and I'll let you know after they respond.
10-11-2005 | 03:14 PM
#90
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Joined: Sep 2005
Posts: 1,987
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From: Missouri
Re: Mhale00 & Raylar Kit
Originally Posted by Steve Zuckerman
Rage:
Keep in mind that all this begins and ends with the propeller. There is more performance to be lost or found here than on any other component on our boats.
Propellers are our version of tires on race cars. The best chassis/engine combo won't work unless it can trasmit it's forces to the pavement.
It has always been my theory to build the "propeller to the boat", not build the boat to the propeller(s).
Propeller technology continues to evolve, just as hull, engine, and drive technologies do. In some cases, propeller technology is catching up to drive and hull technology. Again, I would let Matt and Julie work their magic on your prop(s) before resorting to a lower XD. The other alternative, though expensive, is also preferable in trying/building a 5 blade. What the 5 blade does is add enough blade area, with that extra blade, to carry your hull, even with an elevated XD.
An elevated XD, isn't a bad thing. It's a response by the factory to advancing drive and propeller technology. Also keep in mind that some of this is compromise.........sometimes mods that deliver extra top end, give up some bottom end, and vice versa.
My best friend has a 29' Fountain with the same motor (575SCi) I have. Since I've done my recent round of mods, I can blister him out of the hole, and at pretty much any on plane punch, but he still has 2 or 3 MPH on me top end. His boats slips and cavitates coming on plane (like mine used to).
His boat won't plane off without using tabs. Mine will. They are both great boats, but I've fixed my bottom end and acelleration issues and he hasn't. He doesn't care because he has great top end, and these aren't drag boats. My point is it's hard to have everything, even though we all want it.
Good luck with your Rage and keeps us posted on your progress.
Steve
Keep in mind that all this begins and ends with the propeller. There is more performance to be lost or found here than on any other component on our boats.
Propellers are our version of tires on race cars. The best chassis/engine combo won't work unless it can trasmit it's forces to the pavement.
It has always been my theory to build the "propeller to the boat", not build the boat to the propeller(s).
Propeller technology continues to evolve, just as hull, engine, and drive technologies do. In some cases, propeller technology is catching up to drive and hull technology. Again, I would let Matt and Julie work their magic on your prop(s) before resorting to a lower XD. The other alternative, though expensive, is also preferable in trying/building a 5 blade. What the 5 blade does is add enough blade area, with that extra blade, to carry your hull, even with an elevated XD.
An elevated XD, isn't a bad thing. It's a response by the factory to advancing drive and propeller technology. Also keep in mind that some of this is compromise.........sometimes mods that deliver extra top end, give up some bottom end, and vice versa.
My best friend has a 29' Fountain with the same motor (575SCi) I have. Since I've done my recent round of mods, I can blister him out of the hole, and at pretty much any on plane punch, but he still has 2 or 3 MPH on me top end. His boats slips and cavitates coming on plane (like mine used to).
His boat won't plane off without using tabs. Mine will. They are both great boats, but I've fixed my bottom end and acelleration issues and he hasn't. He doesn't care because he has great top end, and these aren't drag boats. My point is it's hard to have everything, even though we all want it.
Good luck with your Rage and keeps us posted on your progress.
Steve
Thanks Steve!
I clearly understand and agree with what you are saying. I guess along with trying to pick everyones brains in general I guess I am mostly trying to rattle the bushes to find out if the Rage has an 'X' dimension issue and if so what works to fix it. I obviously have heard that the Heat does but so far no one has said anything about the Rage so maybe it does not. It DOES have more slip than I think it should so your comments about high slip with the Heat caught my attention and got me rolling.
The Rage works very good at low end and with an especially pleasing punch at mid range. Top end in the 68 - 71 mph range is very sensitive to load and loading and water conditions. I can run 65 mph all day pretty much regardless of loading. What nags me is a Power Boat Mag test of my identical boat in 2002 on Havasu and recorded 75.6 mph radar (the GPS said 77+mph at 5000 rpm) with a lab finished 26P Bravo 1). That is 82.1 mph theoretical for a 7.9% slip. I'm getting about 15% slip with my 27P Bravo 1 lab finished by the same prop shop that did the 26P lab for the Power Boat test. The stock Bravo 1 26P that came with the boat had ~17% slip. Additionally the Mercury boat speed/slip calculation Web site ball parks the lowest nominal slip numbers at 10-12% for a "heavy" V bottom and 8-9% for a "fast" V bottom boats.
I guess you see why I am on a mission to figure out what is wrong.
Thanks always for the help!
I will talk with Matt and Julie.
